National position statement for the management of latent tuberculosis infection.

UNLABELLED: [Disclaimer: The views expressed in this item are those of the individual authors, and do not necessarily represent the views of the Communicable Diseases Intelligence journal or the Australian Centre for Disease Control. While this Policy and Guidelines item was drafted with consideration to the then-available information on the condition(s) addressed within, it may not be complete and may not represent the currently understood best practice for the referenced condition(s). Readers are advised to refer to the most recent guidance on this matter, where such guidance exists and where its authoritativeness can be established. These guidelines do not replace the need for clinical judgment to be exercised for each individual circumstance, nor the necessity for expert advice to be obtained as appropriate.] The primary role of any tuberculosis (TB) control program is to ensure the prompt identification and effective treatment of active disease. The host immune system often succeeds in containing the initial (or primary) infection with Mycobacterium tuberculosis (Mtb), but may fail to eliminate the pathogen. The persistence of viable organisms explains the potential for the development of active disease years or even decades after infection. This is known as latent tuberculosis infection (LTBI) although, rather than a distinct entity, this probably represents part of a dynamic spectrum. Individuals with LTBI are asymptomatic and it is therefore clinically undetectable. The World Health Organization (WHO) estimates that one-third of the global population has been infected with Mtb, with highest prevalence of LTBI in countries/regions with the highest prevalence of active disease. In 2013, 88% of 1322 notifications in Australia were in the overseas-born population (incidence 19.5 per 100,000 v. 1.0 per 100,000), with this proportion rising over the course of the last decade. Combined with epidemiological evidence of low local transmission, this strongly implies that the vast majority resulted from reactivation of latent infection acquired prior to immigration. Contrasting trends in TB incidence in other developed countries probably reflect differences in policy regarding LTBI.

CONCLUSION: The diagnosis and treatment of LTBI represents an important opportunity for intervention by jurisdictional TB control programs.